Fixed hard disk drive having a removable integrated disc stack structure

Abstract

A hard disk drive, having a removable hard disk stack or assembly in which one or more hard disks are bonded by a compliant bonding agent to a circular hub. Bonding of the hard disk(s) to the hub is the sole support of the hard disks. The circular hub has a center section which is secured by screw threaded attachment to a rotatable member of a motor for rotation at constant speed. The hub center section is of sufficient strength not to deflect in the presence of securing forces. The integrated hard disk(s) and hub provide a hard disk assembly or hard disk stack which, when the hub is attached to the rotatable member, functions as a fixed hard disk assembly providing a fixed, hard disk drive function, while affording ease of removal of the integrated, hard disk assembly for replacement or repair. The hard disk assembly is ideally suited for application in small form factor hard disk drives, less than the 31/2 inch form factor, for example, in the one to two inch form factor range.

We claim: 
     
       1. In a hard disk drive, a hard disk stack structure comprising: a. a substantially circular hub having opposite axially spaced surfaces;   b. at least one hard disk having a central circular opening of lesser diameter than the diameter of said circular hub; and   c. a compliant bonding agent bonding said hard disk adjacent said circular opening to one of said axially spaced surfaces, concentrically with respect to the center of said circular hub and functioning as the sole attachment of said hard disk to said hub.   
     
     
       2. The invention according to claim 1, in which: a. said compliant bonding agent bonding said hard disk adjacent said circular opening comprises a ring of bonding agent concentrically disposed of said circular opening, having an inner diameter greater than said central circular opening of said hard disk and having an outer diameter less than the outer diameter of said circular hub.   
     
     
       3. The invention according to claim 2, in which: a. said bonding agent comprises a two part epoxy resin, comprising resin and a catalyst, mixed in a ration of resin to catalyst by weight in a ratio range of about 1:1.5 to 1:3.   
     
     
       4. In a hard disk drive, a hard disk stack structure, comprising: a. a rotatable member rotatable about an axis;   b. a substantially circular hub having opposite axially spaced surfaces;   c. at least one hard disk having a central circular opening of lesser diameter than the diameter of said circular hub;   d. a compliant bonding agent bonding said hard disk adjacent said circular opening to one of said axially spaced surfaces of said substantially circular hub, concentrically with respect to the center of said hub and functioning as the sole attachment of said hard disk to said hub;   e. means for concentrically positioning said hub on said rotatable member and   f. means for releasably securing said hub to said rotatable member independently of said hard disk.   
     
     
       5. The invention according to claim 4 comprising: a. a second hard disk having a central circular opening of lesser diameter than the diameter of said substantially circular hub; and   b. a compliant bonding agent solely bonding said second hard disk adjacent said circular opening to the remaining surface of said axially spaced surfaces of said substantially circular hub, concentrically with respect to the center of said hub.   
     
     
       6. The invention according to claim 4, in which: a. said hard disk drive is of substantially a 1.3 inch form factor, and   b. said at least one hard disk is about 34 millimeters in diameter.   
     
     
       7. The invention according to claim 4, in which: a. said hard disk drive is of substantially a 1.8 inch form factor, and   b. said at least one hard disk is about 48 millimeters in diameter.   
     
     
       8. The invention according to claim 4, in which: a. said means for concentrically positioning said substantially circular hub on said rotatable member comprises a cylindrical extremity on said rotatable member;   b. said substantially circular hub having a cup-shaped crossection and being disposed in secure contact over said cylindrical extremity of said rotatable member.   
     
     
       9. The invention according to claim 8, in which: a. said means for releasably securing comprises a screw passing through said hub and threaded in an axial direction into said cylindrical extremity of said rotatable member.   
     
     
       10. The invention according to claim 8, in which: a. said means for releasably securing comprises threaded engagement of said hub with said cylindrical extremity of said rotatable member.